Friction reducer performance by complexing multivalent ions in water

Abstract

Embodiments relate to improving the performance of anionic friction reducing polymers in water containing multivalent ions. Exemplary embodiments relate to methods of improving the performance of anionic friction reducing polymers in a subterranean treatment, wherein the method comprises adding a complexing agent to water comprising multivalent ions. The method comprises adding the anionic friction reducing polymer to the water comprising the multivalent ions, wherein the anionic friction reducing polymer is added in an amount less than or equal to about 0.15% by weight of the water. The method comprises introducing the water comprising the multivalent ions, the complexing agent and the anionic friction reducing polymer into at least a portion of the subterranean formation such that the friction reducing polymer reduces energy loss due to turbulence in the water. The complexing agent complexes with at least a portion of the multivalent ions in the water such that the reduction of energy loss by the friction reducing polymer is improved.

1. A method of fracturing a subterranean formation, the method comprising:
 providing a treatment fluid comprising water, multivalent ions in an amount greater than about 10 millimoles per liter of the water, a complexing agent, and an anionic friction reducing polymer in an amount equal to or less than about 0.15% by weight of the treatment fluid, wherein the complexing agent is added to the water in an amount of from about 50% to about 200% of the normality of the multivalent ions in the water, wherein the complexing agent complexes with the multivalent ions such that free multivalent ions are present in an amount equal to or less than about 3 millimoles per liter of the treatment fluid, wherein the complexing agent is selected from the group consisting of a phosphate, a pyrophosphate, an orthophosphate, a citric acid, a gluconic acid, a glucoheptanoic acid, an ethylenediaminetetraacetic acid, a nitrilotriacetic acid, and combinations thereof; and 
 introducing at least a portion of the treatment fluid into the subterranean formation at a pressure sufficient to create or enhance on or more fractures in the subterranean formation, wherein the friction reducing polymer reduces energy loss due to turbulence in the treatment fluid. 
 
     
     
       2. The method of  claim 1 , wherein the multivalent ions comprise calcium ions, wherein the anionic friction reducing polymer comprises acrylamide, and wherein the complexing agent complexes with the multivalent ions such that free multivalent ions in the water are present in an amount of less than about 1 millimole per liter of the treatment fluid. 
     
     
       3. The method of  claim 1  wherein the complexing agent comprises the ethylenediaminetetraacetic acid. 
     
     
       4. The method of  claim 1 , wherein the anionic friction reducing polymer comprises acrylamide. 
     
     
       5. A treatment fluid comprising: water; multivalent ions in an amount greater than about 10 millimoles per liter of the water; a complexing agent; and an anionic friction reducing polymer in an amount equal to or less than about 0.15% by weight of the treatment fluid, wherein the complexing agent is present in an amount of from about 50% to about 200% of the normality of the multivalent ions in the water, wherein the complexing agent complexes with the multivalent ions such that free multivalent ions are present in an amount of less than about 3 millimoles per liter of the treatment fluid, wherein the complexing agent is selected from the group consisting of a phosphate, a pyrophosphate, an orthophosphate, a citric acid, a gluconic acid, a glucoheptanoic acid, an ethylenediaminetetraacetic acid, a nitrilotriacetic acid, and combinations thereof. 
     
     
       6. The treatment fluid of  claim 5  wherein the complexing agent comprises the ethylenediaminetetraacetic acid. 
     
     
       7. The treatment fluid of  claim 5 , wherein the anionic friction reducing polymer comprises acrylamide. 
     
     
       8. A method comprising
 providing a treatment fluid comprising water, multivalent ions in an amount greater than about 10 millimoles per liter of the water, a complexing agent, and an anionic friction reducing polymer in an amount equal to or less than about 0.15% by weight of the treatment fluid, wherein the complexing agent is added to the water in an amount of from about 50% to about 200% of the normality of the multivalent ions in the water; and 
 introducing the treatment fluid into a subterranean formation. 
 
     
     
       9. The method of  claim 8 , wherein the multivalent ions comprise calcium ions, wherein the anionic friction reducing polymer comprises acrylamide, and wherein the complexing agent complexes with the multivalent ions such that free multivalent ions in the water are present in an amount of less than about 1 millimole per liter of the treatment fluid. 
     
     
       10. The method of  claim 8 , wherein the complexing agent is selected from the group consisting of a carbonate, a phosphate, a pyrophosphate, an orthophosphate, a citric acid, a gluconic acid, a glucoheptanoic acid, an ethylenediaminetatracetic acid, a nitrilotriacetic acid, and combinations thereof. 
     
     
       11. The method of  claim 8 , wherein the complexing agent comprises a carbonate. 
     
     
       12. The method of  claim 8 , wherein the complexing agent complexes with the multivalent ions such that free multivalent ions are present in an amount equal to or less than about 3 millimoles per liter of the treatment fluid. 
     
     
       13. The method of  claim 8 , wherein the anionic friction reducing polymer comprises acrylamide. 
     
     
       14. The method of  claim 8 , wherein the treatment fluid is introduced into the subterranean formation at or above a pressure sufficient to create or enhance one or more fractures in the subterranean formation. 
     
     
       15. A method comprising
 adding a complexing agent and an anionic friction reducing polymer to water comprising multivalent ions in an amount greater than about 10 millimoles per liter of the water, wherein the anionic friction reducing polymer is added in an amount equal to or less than about 0.15% by weight of the water, wherein the complexing agent is added to the water in an amount of from about 50% to about 200% of the normality of the multivalent ions in the water, and wherein the complexing agent is added to the water at the same time as the anionic friction reducing polymer is added to the water; and 
 introducing at least a portion of the water comprising the multivalent ions, the complexing agent, and the anionic friction reducing polymer into a subterranean formation. 
 
     
     
       16. The method of  claim 15 , wherein the complexing agent is selected from the group consisting of a carbonate, a phosphate, a pyrophosphate, an orthophosphate, a citric acid, a gluconic acid, a glucoheptanoic acid, an ethylenediaminetatracetic acid, a nitrilotriacetic acid, and combinations thereof. 
     
     
       17. The method of  claim 15 , wherein the complexing agent comprises a carbonate. 
     
     
       18. The method of  claim 15 , wherein the complexing agent complexes with the multivalent ions such that free multivalent ions are present in an amount equal to or less than about 3 millimoles per liter of the treatment fluid. 
     
     
       19. The method of  claim 15 , wherein the anionic friction reducing polymer comprises acrylamide. 
     
     
       20. The method of  claim 15 , wherein the water is introduced into the subterranean formation at or above a pressure sufficient to create or enhance one or more fractures in the subterranean formation.